just train
Instead of using the word challenging you can use the word gifted, special, special gifted.
or
Will, when, why, it, can
There are different adjectives and verbs that can be used instead of the word criss cross. You might use the word intersect, overlap and also network. This would mostly apply to lines or roads. But you can also use the connotation move back and forth through and over which is basically the same thing.
It only looks like a letter X. In fact it is a cross.
I have a stomach ache.
Myself
mixture
are
Another word you can use instead of obituary is "death notice" or "memoriam."
"Ride on the train" is not a word-- it is a phrase. You use it like this: A hundred years ago, when black people wanted to ride on the train, they had to sit in a special "negro" car because the railroads were segregated.
Use the word "how" when asking "in what manner". Use the word "why" when asking "for what reason".